Screw-wrench for grasping cylindrical forms



UNITED STATES 'PATENT OFFICE. F. H. BARTHOLOMEW, OF NEW YORK, Y., AND SOLYMAN MERRICK, 0F SPRINGFIELD,

' MASSACHUSETTS.

SCREW-WRENCH FOR GRASPING CYLINDRICAL FORMS.

To aZZ whom t may concern: j

Be it known that we, FREDERICK H. BAR* THoLoMEW, of New York City, in the county Y Of said dra-wings, Figure l denotes a side elevation of our improved wrench. Fig. 2 is a top view of it. Fig. 3 is a central vertical section.

In said figures A denotes the main bar of the wrench, B the movable nut, C the slide, D the tightening lever, E the spring, F the handle, G the center from which the indented end of the lever `D is described, H the center upon which the lever D turns, I the bolt or other cylindrical substance to be turned.

In the wrench described inthe schedule of the Letters Patent herein above mentioned, for the purpose of turning cylindrical substances, the jaws of the common'wrench are made in such a manner thatwhen the faces are brought in contact they are not parallel but form an angle; one of the faces is indented or roughened and the other left smooth, so that by turning the wrench in the proper direction, the bolt or cylinder to be turned is drawn in between the two faces and held firmly. It is found in practice that when the wrench has been long, in use, the smooth face becomes somewhat roughened, and when the motion of the wrench is reversed for the purpose of taking a new hold of the cylinder, the friction on the smooth face is so great as to draw it partially back in a contrary direction to the one desired. In order to remedy this defect we form an angle in the main bar of the wrench as shown at J; we then" make the slide C to move easily backward and forward on that part of the bar upon which the screw is cut; to the slide C we attach the lever D by ka joint as shown at H. which lever is-pressed down upon the main bar' by the spring E, i

which spring is made fast to the lever D and-bears'kupon the slide C; the end of the lever D is made circular (the center'of which circle is shown at G) for the purpose of'pressing more firmly against the cylinder as the end of the lever is forced down toward the main bar; 'the circular yend of the lever is also indented or roughened thatA it may not slip on the cylinder. The screw is cutupon two opposite sides of the main bar and the movable nut fitted to it as in the ordinary screw wrench; the handle is also attached in the usual way; but to con# nect the slide C with the movable nut, we make a portion ofthe slide to project a short dist-ance toward the handle; underneath this projection 4we cut a groove a short distance from the end; we also turn a Y groove near the end ofthe nut; the collar of the nut thus formed takes into the groove in the slide, and the projection on the end of theslide takes into the groovein the nut as shown at K Fig. land Fig. 3.

To operate our wrench, we placeithe mainV bar upon the cylindrical 4nut or bolt as shown at I Fig. 1; we then advance the lever D by means of the movable nut, until the indented end of t-he lever comes in contact with the cylinder; we then draw the handle the main bar; we then draw the handle inA the direction indicated by the arrow, which causes the lever to take la firm holdof the cylinder and carry it around in the direction of the arrow, and by reversing the motion of the handle the cylinder is instantly released. l

Wha-t we claim in the above described wrench, and for the purpose of holding and turning cylindrical substances, is-

The 'combination of the lever kD with the mainbar of the wrench, alsowith the slide C, the nut B and the as herein described.

' F. H. BARTHOLOMEW.

SOLYMAN MERRICK. Witnesses GEO. IRELAND, Jr., J As. P. HOWARD.

spring E, substantial ly 

